【摘要】 电荷耦合是适用于中等电压功率MOSFET设计的先进设计理念之一,该设计思想旨在改善器件阻断态下的电场分布从而提高耐压。针对150 V电荷耦合功率MOSFET双外延漂移区(分别为电荷耦合区N1区与非耦合区N2区)电荷匹配问题进行了仿真优化研究,结果表明:N1区和N2区浓度分别约为2.2×1016cm-3和4.5×101 5cm-3时,电场分布更加均匀、耐压更高,且比导通电阻仅为1.306 mΩ·cm2,即击穿电压和比导通电阻间达到最佳匹配。同时,还针对器件不同槽深进行了静态特性和动态特性的整体仿真优化研究,结果表明:槽深在7~9μm时,器件满足耐压要求且击穿电压随双漂移区掺杂浓度匹配程度变化较为平稳。最后,优化结构与传统槽栅MOSFET相比,其栅漏电容和栅电荷大幅降低,器件优值降低了约87%。更多还原

【Abstract】 Charge coupling is one of the advanced design concept for medium voltage power MOSFET.The electric field distribution in the blocking state can be improved and the breakdown voltage can be increased by using the design.For the charge matching problem,a 150 V charge coupling power MOSFET utilizing double epitaxial drift region(charge coupling region N1 and uncoupling region N2respectively) was simulated and optimizated.The results show that the device has more uniform electric field distribution and higher breakdown voltage under the doping concentrations of N1 region,N2region are about 2.2 × 1016cm-3,4.5 × 101 5cm-3and the specific on-resistance is only 1.306 mΩ·cm2.In other words,the breakdown voltage and specific on-resistance achieve the best matching.Moreover,the effects of trench depth on static and dynamic characteristic of the device were simulated and optimizatied comprehensively.The results show that the device structure meet breakdown voltage requirement under the trench depth of 7-9 μm and the breakdown voltage increased smoothly with double drift region doping concentration matching level changed.Finally,the optimum structure compared with conventional trench gate power MOSFET.The results show that the gate-drain capacitance and gate charge are greatly decreased and the figure of merit almost reduced about 87% of the optimum structure.更多还原